Hydraulic steering devices comprise a hydraulic actuator destined for functioning in two opposite directions, generally constituted by a piston cylinder group with a through-stem, which is connected to the steering linkage.
The oil is sent to the hydraulic actuator by a distributor device which rotates internally of a fixed body to which the oil supply pump leads.
The rotary distributor sends controlled quantities of pressurised hydraulic fluid under pressure to the actuator to which it is connected, and sends the fluid coming from the actuator in discharge.
The present invention relates specifically to jacket-type rotary distributors, which comprise, internally of the fixed body, two sealedly coupled concentric cylindrical elements which are destined to take on various angular positions in relation to one another.